An abstract implementation of OLE control, which allows to create new OLE control from a Swing component.
This is a helper class that provides a basic implementation of IOleObject, IViewObject2 and IOleInPlaceObject interfaces which
are required for implpementation of an OLE control.

Any derived class should implement initUI() method. It is designed to create a Swing UI of the OLE component.
The getContentWindow() provides an access to a content window.